is there any truth in the claims that the .64wave has higher gain and is this so called gain at a lower angle than the 5/8 or is this just more of the cbradio b/s, i can find plenty of info on 5/8vs1/2 at different ground heights but not one article on the .64wave antenna, can somebody post a link from a qualified independant source, thanks.
-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
5/8wave vs .64wave
- Thread starter bob85
- Start date
unusual looking antenna there eduk8tr, i would like to see that modeled against a 5/8 to see if theres any truth in the makers claims, i have looked high and low but cant find any info other than from the different manufacturers, i have plenty of antennas for parts to build just about any style vertical i want but i would like some hard qualified facts to ponder over first, theres nothing to read about the old ham international bigmac 7/8 which worked fantastic or the avanti style antennas which i like too, then theres the jogunn 3/4 the point64 and coily's .64wave to consider, i could easilly lengthen my i10k to .64 and retune with that superb trombone, i can find nothing more than supposition from other operators most of which have never tried a quarter of the antennas i have owned over nearly 30 years, the only qualified design seems to be the 5/8 and out of the half dozen or more 5/8's i have used the i10k is the best performer and looks the strongest of all the antennas i owned, if anybody has a modelling prog thats understandable pls point me in the right direction i want to play with some different designs for my own knowledge.
Bob85,
You can read 3 different articles or talk to 3
different people and get 3 different answers.
If i were you i would just design and build it.
Form your own opinion by seeing first-hand
how it performs compared to a 5/8 wave.
I personally don't care for most theory, i
like to see real life facts and performance.
I have never ran across any articles that would
help you out.
Good Luck and keep me posted on your progress
and results. Thanks.
You can read 3 different articles or talk to 3
different people and get 3 different answers.
If i were you i would just design and build it.
Form your own opinion by seeing first-hand
how it performs compared to a 5/8 wave.
I personally don't care for most theory, i
like to see real life facts and performance.
I have never ran across any articles that would
help you out.
Good Luck and keep me posted on your progress
and results. Thanks.
I have talked to a few people that claim the
I-10K will out-perform the Wolf-point antenna
mentioned above.
I have never tested these 2 antennas, so, i can
not say whether it will or it won't.
I-10K will out-perform the Wolf-point antenna
mentioned above.
I have never tested these 2 antennas, so, i can
not say whether it will or it won't.
bob85,
Lets see. 5/8 wave is the same as .625 wave. Then, .64 - .625 = 0.015 wave length. Then, .015 wave length times 18 feet (roughly) = 3 inches. Hmmm, hope the amount of gain ~claimed~ isn't much, cuz it certainly won't be much different than a 5/8 wave. The most appreciable difference would be in the radiation pattern. Well, let me take that back, cuz there isn't much difference there either. [An appreciable amount of difference amounts to something like 3 db, I'd think. Which is not really that noticable unless you're glued to that meter.]
As has been said, if the .64 hears better than the 5/8 wave, then it's probably worth something. If it doesn't, then why bother? The amount of difference under ideal conditions is going to be some fraction of a db, not a multiple. If that makes a difference to you then your ears are much better than mine.
Now, if the $$$ of the .64 wave antenna is much less than the 5/8 wave, DO IT! If not, well...
- 'Doc
Lets see. 5/8 wave is the same as .625 wave. Then, .64 - .625 = 0.015 wave length. Then, .015 wave length times 18 feet (roughly) = 3 inches. Hmmm, hope the amount of gain ~claimed~ isn't much, cuz it certainly won't be much different than a 5/8 wave. The most appreciable difference would be in the radiation pattern. Well, let me take that back, cuz there isn't much difference there either. [An appreciable amount of difference amounts to something like 3 db, I'd think. Which is not really that noticable unless you're glued to that meter.]
As has been said, if the .64 hears better than the 5/8 wave, then it's probably worth something. If it doesn't, then why bother? The amount of difference under ideal conditions is going to be some fraction of a db, not a multiple. If that makes a difference to you then your ears are much better than mine.
Now, if the $$$ of the .64 wave antenna is much less than the 5/8 wave, DO IT! If not, well...
- 'Doc
doc i dont know what i was thinking lol i make it just over 6 inches longer at 27.500 you used .015 of a halfwave, for some unknown reason i had the idea that the .64 was a couple of feet longer because the imax is 24feet and people call it a .64wave where my i10k is nearer 21feet plus the caphat but you woke me up i got the calculator out and its nearer 6 or 7 inches difference, i am still looking for info, how the hell do you use this eznec4 program its double dutch to me i cant even see how to input a 5/8 groundplane let alone play with radial angles, theres got to be an easier program than this that will model the antennas i listed above.
Bob85,
The Imax 2000 is 24 ft long. But, the actual
total radiating element inside the Imax is
270.5 inches. Alittle over 22 ft.
The Imax 2000 is 24 ft long. But, the actual
total radiating element inside the Imax is
270.5 inches. Alittle over 22 ft.
Also one important point to remember is that a 1/4 wave ground plane will present a more circular pattern in a favorable installation. and the 5/8 and .64 will present lobes and nulls in its patterns, the lobes are usually represented as gain.
Just something to add to the equation.
Jonbah
CDX 3030
Just something to add to the equation.
Jonbah
CDX 3030
hey Bob..
keep it simple...
buy Jay's Interceptor I-10K ..
i do not think there is a better vertical on the market as far as base antennas go..
as far as i remember..
one is to go no more then .64 wave length ..
otherwise one gets unfavorable nulls ..
i can for sure say..
Jay's Interceptor I-10K
Simply works
and works very very well indeed
Later
keep it simple...
buy Jay's Interceptor I-10K ..
i do not think there is a better vertical on the market as far as base antennas go..
as far as i remember..
one is to go no more then .64 wave length ..
otherwise one gets unfavorable nulls ..
i can for sure say..
Jay's Interceptor I-10K
Simply works
and works very very well indeed
Later
bob85,
A half wave, good grief. Some days are like that, and some days I'm even worse. Oh well, I did say 'roughly'...
I've tried 'eznex' and don't care for it. I use one called "NecforWin". Doesn't require as much effort (sort of) and gives about the same results (sort of). Not free, but worth the price, I think. Go to the 'eznec' website, there are kinds of help files (not optional, you have to read the book!). It's a good program. Not easy to pick up, but once the light bulb goes on, you wonder why it was so difficult to start with... sort of.
- 'Doc
A half wave, good grief. Some days are like that, and some days I'm even worse. Oh well, I did say 'roughly'...
I've tried 'eznex' and don't care for it. I use one called "NecforWin". Doesn't require as much effort (sort of) and gives about the same results (sort of). Not free, but worth the price, I think. Go to the 'eznec' website, there are kinds of help files (not optional, you have to read the book!). It's a good program. Not easy to pick up, but once the light bulb goes on, you wonder why it was so difficult to start with... sort of.
- 'Doc
Before any of us were born, test were performed on different antenna systems. It was discovered that the maximum antenna gain possible for a single monopole was with a radiator, .64 wave length long. Broadcast stations have been using .64 wave length for DECADES.
In the CB market, we had 1/4 wave and 1/2 wave antennas. It was easier for the intended market to understand a 5/8 wave. Eccentially, it is the same as a .64 wave. As it was correctly pointed out by Doc, it's .625 vs .640, or a difference of .015 wave. As Bob correctly pointed out, that's about 6 to 8 inches.
To answer your question, and this was proven back in the 1930's, the MAXIMUM amount of gain possible is with a .64 wave length radiator. After that, the bubble breaks and the signal pattern becomes "distorted". So its clear that a .640 wave has more gain than a .625 wave. How much? Nothing to write home about. I'd guess you would be hard to measure it.
When the I-10K first came out, I spoke with Jay about using .64 in his calculations instead of .625 (owners will know what I'm speaking about, its in the TUNING SECTION of the manual). He said you could do that, but why?
My unscientific reasoning for sticking with .625 is that it buys me a little margin before breaking that bubble. For argument sake, what if you messed up your measurements and were at .65 wave? You broke the bubble!
This is picking a knat's ass, but those hose clamps add to the surface area of the radiator. Is it enough to constitute .015 wave? I don't know. Best to play it safe with .625 wave and not worry about breaking the bubble.
For the hardcore people out there, you need to adjust your radiator while watching the field strength, and re-adjusting for best SWR as you go. At some point you will see a peak. That's where you want it! Of course, Jay already did that for you which explains why it took 4 years for the production model to come to market.
This is not a perfect science. General rules apply. There is essentially NO difference between .640 and .625 (5/8).
The Wolf .64 antenna is a loaded antenna fed by a gamma match. That's 2 strikes! I hear he is a great guy and builds a good antenna, but it is still a loaded, gamma fed antenna.
In the CB market, we had 1/4 wave and 1/2 wave antennas. It was easier for the intended market to understand a 5/8 wave. Eccentially, it is the same as a .64 wave. As it was correctly pointed out by Doc, it's .625 vs .640, or a difference of .015 wave. As Bob correctly pointed out, that's about 6 to 8 inches.
To answer your question, and this was proven back in the 1930's, the MAXIMUM amount of gain possible is with a .64 wave length radiator. After that, the bubble breaks and the signal pattern becomes "distorted". So its clear that a .640 wave has more gain than a .625 wave. How much? Nothing to write home about. I'd guess you would be hard to measure it.
When the I-10K first came out, I spoke with Jay about using .64 in his calculations instead of .625 (owners will know what I'm speaking about, its in the TUNING SECTION of the manual). He said you could do that, but why?
My unscientific reasoning for sticking with .625 is that it buys me a little margin before breaking that bubble. For argument sake, what if you messed up your measurements and were at .65 wave? You broke the bubble!
This is picking a knat's ass, but those hose clamps add to the surface area of the radiator. Is it enough to constitute .015 wave? I don't know. Best to play it safe with .625 wave and not worry about breaking the bubble.
For the hardcore people out there, you need to adjust your radiator while watching the field strength, and re-adjusting for best SWR as you go. At some point you will see a peak. That's where you want it! Of course, Jay already did that for you which explains why it took 4 years for the production model to come to market.
This is not a perfect science. General rules apply. There is essentially NO difference between .640 and .625 (5/8).
The Wolf .64 antenna is a loaded antenna fed by a gamma match. That's 2 strikes! I hear he is a great guy and builds a good antenna, but it is still a loaded, gamma fed antenna.
B
BOOTY MONSTER
Guest
"To answer your question, and this was proven back in the 1930's, the MAXIMUM amount of gain possible is with a .64 wave length radiator. After that, the bubble breaks and the signal pattern becomes "distorted"."
i guess they didn't have sigma 4 antennas yet in 1930 .
They hadn't captured any martians yet and did not have the technology that the gerries and the japs had.
"To answer your question, and this was proven back in the 1930's, the MAXIMUM amount of gain possible is with a .64 wave length radiator. After that, the bubble breaks and the signal pattern becomes "distorted"."
i guess they didn't have sigma 4 antennas yet in 1930 .
Hey BM, IMO old Master Chef was full-of-it. He never gave us anything but "words" to support his claims. That is typical as things tend to go on these CB forums, but he is only partly right in his claim...regarding a distortion bubble in the pattern for radiators longer than .64 wl.
That said, when using Eznec5 modeling, I find that my Sigma4 model does produce a very strange pattern distortion when connected to the Earth via a supporting mast, was set near a full wavelength or less at 33'-36' in height, and again at 2 wavelengths or less at 67'-72'. When I set this antenna shorter or longer than these particular full wavelength heights...the patterns tend to return to what might look more like a normal pattern, one that we might expect.
I can't explain technically what happens when I set my Sigma4 model at these heights, but the patterns produced are pretty much as Master Chef suggested. So, if he and Jay actually saw a 5/8 wave vertical monopole modeled, side by side along with a 3/4 wave antenna similar to a Sigma4, and the models were set at a height near a wavelength or multiple thereof, then this might explain what they saw and thus their claims.
BM, who is they?
View attachment Sigma4 at 36' & 37'.pdf
This skewing of the pattern is similar or worse at about 72' feet.
Last edited: